Pure Technical Efficiency scores of Austrian dairy farms are estimated econometrically on the basis of data envelopment analysis and bootstrapping. In a second stage, using the same assumptions on the distribution of error terms, the distances of farms to their production possibility curve are estimated as functions of farm attributes. Since some of these attributes refer to natural conditions which are more or less unfavourable, the farms in the sample are facing individual frontiers. The distinction between sectorial and individual frontiers gives rise to a distinction between “overall” and “firm-level” efficiency. Using overall efficiency for the calculation of possible savings from a move to the frontier will overestimate these savings and underestimate the efficiency of a farm relative to the conditions in which it operates.